Inhibin, beta B subunit (IPR000381)
Short name: Inhibin_betaB
Overlapping homologous superfamilies
- Transforming growth factor-beta-related (IPR015615)
- Inhibin, beta B subunit (IPR000381)
Inhibins and activins are glycoproteins, secreted by the gonads, that belong to the transforming growth factor beta family [PMID: 2417121]. They participate in differentiation and growth of diverse cell types. Inhibin inhibits secretion of follicle-stimulating hormone by the pituitary [PMID: 9207855].
Inhibin has two isoforms, A and B, with the same alpha subunit but different beta subunits. Inhibin A is a dimer of alpha and beta A subunits, inhibin B is a dimer of alpha and beta B subunits.
Activin A is a dimer of beta A subunits, activin AB is a dimer of beta A and beta B chains.
Follistatin is bound to inhibin and activin and indirectly modulates the FSH release. In turn, FSH stimulates inhibin gene expression in the ovarian follicle [PMID: 7813465], probably mediated by cAMP [PMID: 2417121]. The serum levels of inhibin, activin, and follistatin are elevated in pregnant women and decrease after delivery [PMID: 9989858].
Genes coding for mouse activin beta C and beta E are closely linked and exhibit a liver-specific expression pattern in adult tissues.